Yes. Before my body kit came in, I masked everything off and shot it with 2 coats primer and two coats expensive MB paint only to find that it looked better with just the primer and a clear coat. That black gravel guard is a mofo. Very absorbent. I would try to match the paint with a comparable gray primer and shoot a few coats. Also because of the gravel guards soft properties, you'll be doing a lot of touch ups.It looked 1000 times better than the black though. This is the only pic I could find (Ironically the boxes contain two Carlsson kits)
People are always selling their AMG side skirts. I'd ask around here, you might find them already painted your color.